The present invention relates to improved cookware, particularly to cooking vessels, such as pots and pan with superior durability and extended lifetimes of use.
Prior methods of constructing cookware involve forming a pot or pan from a single sheet of stainless steel, aluminum or copper, which may include a laminate construction. Preferably, the pans bottom is constructed totally of either aluminum or copper, or a laminated construction thereof to provide improved heat transfer to rapidly heat the pan, for quick responsiveness to the applied heat, and evenly heat the foodstuff contained therein.
Recently anodized aluminum pans have found favor in the marketplace, due to the initial appearance in a dark gray or charcoal color, and superior hardness of the surface that avoids marring or scratching from cleaning or scraping with cooking utensils. Anodized aluminum pans also offer superior durability with respect to resisting mars and scratch on the outside, due to contact with burner elements, flames or metal structures used to support the cooking vessel above a burner's flames. The superior hardness results from the anodizing process which forms a hard and well adhered out layer of aluminum oxide, a ceramic material that is several time harder than stainless steel as well as the much softer aluminum.
Although anodized aluminum cookware offers many advantages, it can also have disadvantages for some consumers. For example, the pots are considerably heavier despite the lower density of aluminum as compared to stainless steel, as the walls need to be sufficiently thick to insure structural integrity, whereas a laminate of stainless steel cladding an aluminum or aluminum/copper composite bottom pan is significantly lighter. Although anodized pans are initially of a pleasing appearance, they do stain and tarnish readily when high acidity foods are cooked therein. While stainless steel offers excellent chemical resistance it can only be readily be combined with a non-anodized aluminum exterior, as the anodizing process itself is entirely corrosive to stainless steel.
It is thus an object of the present invention to provide cooking pans with superior exterior durability and hardness that are resistant to stains from acidic foods.
It is also an object to provide pans of high durability that have an interior surface that is more stain resistant than conventional anodized aluminum cookware, but have an anodized exterior aluminum surface providing both a durable and pleasing outer surface appearance, being substantially free from mars and scratch that affect softer metal finishes.